Patterns of conflict and conflict resolution in the parent-child relationship undoubtedly impact on the relationships between siblings. The aim of this research is to examine the links between mother-child interactions and sibling interactions in the domains of conflict and interpersonal problem-solving. These patterns of behavior are examined in normal families and in families in which there is maternal depression. Siblings (2-3 years old and 5-7 years old) are observed in interaction with each other, individually with the mother, and together with the mother. Children's interpretations of conflict situations and understanding of others' emotions are also evaluated. High levels of conflict have been observed in some siblings with a depressed mother. Also interpretations of affect in projective tests suggest more disturbance and deviant themes in children with a depressed caregiver. Sex differences in patterns of conflict and negotiation of problems are of special interest because of their relevance to the differential development in the two sexes of antisocial and depressive disorders. Preliminary analyses indicate early sex differences in children's patterns of conflict resolution. Boys adopt more assertive and aggressive strategies for solving interpersonal problems while girls adopt more affiliative and submissive strategies for resolving conflicts.